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la Marca G, Carling RS, Moat SJ, Yahyaoui R, Ranieri E, Bonham JR, Schielen PCJI. Current State and Innovations in Newborn Screening: Continuing to Do Good and Avoid Harm. Int J Neonatal Screen 2023; 9:ijns9010015. [PMID: 36975853 PMCID: PMC10057559 DOI: 10.3390/ijns9010015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 03/29/2023] Open
Abstract
In 1963, Robert Guthrie's pioneering work developing a bacterial inhibition assay to measure phenylalanine in dried blood spots, provided the means for whole-population screening to detect phenylketonuria in the USA. In the following decades, NBS became firmly established as a part of public health in developed countries. Technological advances allowed for the addition of new disorders into routine programmes and thereby resulted in a paradigm shift. Today, technological advances in immunological methods, tandem mass spectrometry, PCR techniques, DNA sequencing for mutational variant analysis, ultra-high performance liquid chromatography (UPLC), iso-electric focusing, and digital microfluidics are employed in the NBS laboratory to detect more than 60 disorders. In this review, we will provide the current state of methodological advances that have been introduced into NBS. Particularly, 'second-tier' methods have significantly improved both the specificity and sensitivity of testing. We will also present how proteomic and metabolomic techniques can potentially improve screening strategies to reduce the number of false-positive results and improve the prediction of pathogenicity. Additionally, we discuss the application of complex, multiparameter statistical procedures that use large datasets and statistical algorithms to improve the predictive outcomes of tests. Future developments, utilizing genomic techniques, are also likely to play an increasingly important role, possibly combined with artificial intelligence (AI)-driven software. We will consider the balance required to harness the potential of these new advances whilst maintaining the benefits and reducing the risks for harm associated with all screening.
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Affiliation(s)
- Giancarlo la Marca
- Newborn Screening, Clinical Chemistry and Pharmacology Lab, IRCCS Meyer Children's University Hospital, 50139 Florence, Italy
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, 50139 Florence, Italy
| | - Rachel S Carling
- Biochemical Sciences, Viapath, Guys & St Thomas' NHSFT, London SE1 7EH, UK
- GKT School of Medical Education, Kings College London, London SE1 1UL, UK
| | - Stuart J Moat
- Department of Medical Biochemistry, Immunology & Toxicology, University Hospital Wales, Cardiff CF14 4XW, UK
- School of Medicine, Cardiff University, University Hospital Wales, Cardiff CF14 4XW, UK
| | - Raquel Yahyaoui
- Laboratory of Metabolic Disorders and Newborn Screening Center of Eastern Andalusia, Málaga Regional University Hospital, Institute of Biomedical Research in Malaga (IBIMA-Plataforma BIONAND), Avenida Arroyo de los Angeles s/n, 29011 Malaga, Spain
| | - Enzo Ranieri
- Biochemical Genetics, Genetics and Molecular Pathology, SA Pathology, Women's & Children's Hospital, Adelaide 5043, Australia
| | - James R Bonham
- Sheffield Children's NHS Foundation Trust, Western Bank, Sheffield S10 2TH, UK
| | - Peter C J I Schielen
- International Society for Neonatal Screening, Reigerskamp 273, 3607 HP Stichtse Vecht, The Netherlands
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Divyapicigil M, Pirincci Gokturk SS, Ergenoglu B, Yucel F, Akcael EA. Development of mutant human immunoreactive trypsinogen 1 (IRT1) and mutant human immunoreactive trypsinogen 2 (IRT2) for use in immunoassays. Protein Expr Purif 2020; 169:105572. [PMID: 31972264 DOI: 10.1016/j.pep.2020.105572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 01/05/2020] [Accepted: 01/17/2020] [Indexed: 10/25/2022]
Abstract
Immunoreactive Trypsinogen (IRT) is a protein-based pancreatic proenzyme that has an important role in protein digestion in humans. In human body, once IRT present in the small intestine, the proteolytic cleavage activates trypsinogen into trypsin. When IRT is in the active form, it is capable to cleave antibodies, other proteins and even itself while it is desired to use in immunoassays. According to the literature, there are three important IRT isoforms called Immunoreactive Trypsinogen 1 (IRT1), Immunoreactive Trypsinogen 2 (IRT2), and Immunoreactive Trypsinogen 3 (IRT3). However, trypsinogen 1 (cationic trypsinogen, IRT1) and trypsinogen 2 (anionic trypsinogen, IRT2) are the major isoforms in human pancreatic juice and used in the diagnosis of cystic fibrosis (CF). In this study, it is aimed to restrain its proteolytic activity with K23D mutation, which changes lysine (K) residue at the 23rd position to aspartic acid (D). Because we wanted to produce a hassle-free human recombinant immune reactive trypsinogen proenzyme which has similar antigenic properties with the native form. It is also aimed that the mutant IRTs do not exhibit proteolytic activity for the development of durable detection kits with a longer shelf life for both two isoforms. The innovation was actualized in order to use IRTs as a standard antigen in Immunoassays such as ELISA kits. The gene was synthesized as mutated and expressed in P. pastoris X-33 strain. The loss of proteolytic activity has been proven with the BAEE test. Antigenic properties of K23D IRTs and the effect of proteolytic inactivation on their performance in immunoassays were assessed with ELISA and Western Blot. In ELISA results K23D mutated IRTs showed higher signals than Wild-Type forms.
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Affiliation(s)
- Mustafa Divyapicigil
- The Scientific and Technological Research Council of Turkey (TÜBİTAK), Marmara Research Center, Genetic Engineering and Biotechnology Institute, Gebze, Kocaeli, Turkey; The University of Alabama, Department of Biological Sciences, Tuscaloosa, AL, USA.
| | - Serife Seyda Pirincci Gokturk
- The Scientific and Technological Research Council of Turkey (TÜBİTAK), Marmara Research Center, Genetic Engineering and Biotechnology Institute, Gebze, Kocaeli, Turkey.
| | - Bengu Ergenoglu
- The Scientific and Technological Research Council of Turkey (TÜBİTAK), Marmara Research Center, Genetic Engineering and Biotechnology Institute, Gebze, Kocaeli, Turkey.
| | - Fatima Yucel
- The Scientific and Technological Research Council of Turkey (TÜBİTAK), Marmara Research Center, Genetic Engineering and Biotechnology Institute, Gebze, Kocaeli, Turkey.
| | - Esin Aslankaraoglu Akcael
- The Scientific and Technological Research Council of Turkey (TÜBİTAK), Marmara Research Center, Genetic Engineering and Biotechnology Institute, Gebze, Kocaeli, Turkey.
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Newborn blood spot screening for cystic fibrosis with a four-step screening strategy in the Netherlands. J Cyst Fibros 2019; 18:54-63. [DOI: 10.1016/j.jcf.2018.07.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 07/09/2018] [Accepted: 07/16/2018] [Indexed: 12/27/2022]
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Genomic sequencing in cystic fibrosis newborn screening: what works best, two-tier predefined CFTR mutation panels or second-tier CFTR panel followed by third-tier sequencing? Genet Med 2017; 19:1159-1163. [PMID: 28471435 DOI: 10.1038/gim.2017.32] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 02/06/2017] [Accepted: 02/09/2017] [Indexed: 01/08/2023] Open
Abstract
PurposeThe purpose of this study was to model the performance of several known two-tier, predefined mutation panels and three-tier algorithms for cystic fibrosis (CF) screening utilizing the ethnically diverse California population.MethodsThe cystic fibrosis transmembrane conductance regulator (CFTR) mutations identified among the 317 CF cases in California screened between 12 August 2008 and 18 December 2012 were used to compare the expected CF detection rates for several two- and three-tier screening approaches, including the current California approach, which consists of a population-specific 40-mutation panel followed by third-tier sequencing when indicated.ResultsThe data show that the strategy of using third-tier sequencing improves CF detection following an initial elevated immunoreactive trypsinogen and detection of only one mutation on a second-tier panel.ConclusionIn a diverse population, the use of a second-tier panel followed by third-tier CFTR gene sequencing provides a better detection rate for CF, compared with the use of a second-tier approach alone, and is an effective way to minimize the referrals of CF carriers for sweat testing. Restricting screening to a second-tier testing to predefined mutation panels, even broad ones, results in some missed CF cases and demonstrates the limited utility of this approach in states that have diverse multiethnic populations.
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Hendrix MM, Foster SL, Cordovado SK. Newborn Screening Quality Assurance Program for CFTR Mutation Detection and Gene Sequencing to Identify Cystic Fibrosis. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2016; 4. [PMID: 28261631 PMCID: PMC5332130 DOI: 10.1177/2326409816661358] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
All newborn screening laboratories in the United States and many worldwide screen for cystic fibrosis. Most laboratories use a second-tier genotyping assay to identify a panel of mutations in the CF transmembrane regulator (CFTR) gene. Centers for Disease Control and Prevention’s Newborn Screening Quality Assurance Program houses a dried blood spot repository of samples containing CFTR mutations to assist newborn screening laboratories and ensure high-quality mutation detection in a high-throughput environment. Recently, CFTR mutation detection has increased in complexity with expanded genotyping panels and gene sequencing. To accommodate the growing quality assurance needs, the repository samples were characterized with several multiplex genotyping methods, Sanger sequencing, and 3 next-generation sequencing assays using a high-throughput, low-concentration DNA extraction method. The samples performed well in all of the assays, providing newborn screening laboratories with a resource for complex CFTR mutation detection and next-generation sequencing as they transition to new methods.
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Improving newborn screening for cystic fibrosis using next-generation sequencing technology: a technical feasibility study. Genet Med 2015; 18:231-8. [PMID: 25674778 DOI: 10.1038/gim.2014.209] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 12/22/2014] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Many regions have implemented newborn screening (NBS) for cystic fibrosis (CF) using a limited panel of cystic fibrosis transmembrane regulator (CFTR) mutations after immunoreactive trypsinogen (IRT) analysis. We sought to assess the feasibility of further improving the screening using next-generation sequencing (NGS) technology. METHODS An NGS assay was used to detect 162 CFTR mutations/variants characterized by the CFTR2 project. We used 67 dried blood spots (DBSs) containing 48 distinct CFTR mutations to validate the assay. NGS assay was retrospectively performed on 165 CF screen-positive samples with one CFTR mutation. RESULTS The NGS assay was successfully performed using DNA isolated from DBSs, and it correctly detected all CFTR mutations in the validation. Among 165 screen-positive infants with one CFTR mutation, no additional disease-causing mutation was identified in 151 samples consistent with normal sweat tests. Five infants had a CF-causing mutation that was not included in this panel, and nine with two CF-causing mutations were identified. CONCLUSION The NGS assay was 100% concordant with traditional methods. Retrospective analysis results indicate an IRT/NGS screening algorithm would enable high sensitivity, better specificity and positive predictive value (PPV). This study lays the foundation for prospective studies and for introducing NGS in NBS laboratories.
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van der Ploeg CPB, van den Akker-van Marle ME, Vernooij-van Langen AMM, Elvers LH, Gille JJP, Verkerk PH, Dankert-Roelse JE. Cost-effectiveness of newborn screening for cystic fibrosis determined with real-life data. J Cyst Fibros 2014; 14:194-202. [PMID: 25213034 DOI: 10.1016/j.jcf.2014.08.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/19/2014] [Accepted: 08/19/2014] [Indexed: 12/01/2022]
Abstract
BACKGROUND Previous cost-effectiveness studies using data from the literature showed that newborn screening for cystic fibrosis (NBSCF) is a good economic option with positive health effects and longer survival. METHODS We used primary data to compare cost-effectiveness of four screening strategies for NBSCF, i.e. immunoreactive trypsinogen-testing followed by pancreatitis-associated protein-testing (IRT-PAP), IRT-DNA, IRT-DNA-sequencing, and IRT-PAP-DNA-sequencing, each compared to no-screening. A previously developed decision analysis model for NBSCF was fed with model parameters mainly based on a study evaluating two novel screening strategies among 145,499 newborns in The Netherlands. RESULTS The four screening strategies had cost-effectiveness ratios varying from €23,600 to €29,200 per life-year gained. IRT-PAP had the most favourable cost-effectiveness ratio. Additional life-years can be gained by IRT-DNA but against higher costs. When treatment costs reduce with 5% due to early diagnosis, screening will lead to financial savings. CONCLUSION NBSCF is as an economically justifiable public health initiative. Of the four strategies tested IRT-PAP is the most economic and this finding should be included in any decision making model, when considering implementation of newborn screening for CF.
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Affiliation(s)
| | | | - A M M Vernooij-van Langen
- Department of Research and Innovation, Atrium Medical Center, Heerlen, The Netherlands; Laboratory for Infectious Diseases and Perinatal Screening, RIVM, Bilthoven, The Netherlands
| | - L H Elvers
- Laboratory for Infectious Diseases and Perinatal Screening, RIVM, Bilthoven, The Netherlands
| | - J J P Gille
- Department of Clinical Genetics, VU University Medical Center, Amsterdam, The Netherlands
| | - P H Verkerk
- Department of Child Health, TNO, Leiden, The Netherlands
| | - J E Dankert-Roelse
- Department of Pediatrics, Atrium Medical Center, Heerlen, The Netherlands
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Newborn screening for cystic fibrosis in Switzerland — Consequences after analysis of a 4 months pilot study. J Cyst Fibros 2013; 12:667-74. [DOI: 10.1016/j.jcf.2013.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 02/22/2013] [Accepted: 04/22/2013] [Indexed: 01/22/2023]
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Barben J, Gallati S, Fingerhut R, Schoeni MH, Baumgartner MR, Torresani T. Retrospective analysis of stored dried blood spots from children with cystic fibrosis and matched controls to assess the performance of a proposed newborn screening protocol in Switzerland. J Cyst Fibros 2012; 11:332-6. [DOI: 10.1016/j.jcf.2012.01.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 11/12/2011] [Accepted: 01/10/2012] [Indexed: 11/30/2022]
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Optimal DNA tier for the IRT/DNA algorithm determined by CFTR mutation results over 14 years of newborn screening. J Cyst Fibros 2011; 10:278-81. [PMID: 21388895 DOI: 10.1016/j.jcf.2011.02.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 01/08/2011] [Accepted: 02/02/2011] [Indexed: 11/21/2022]
Abstract
BACKGROUND There has been great variation and uncertainty about how many and what CFTR mutations to include in cystic fibrosis (CF) newborn screening algorithms, and very little research on this topic using large populations of newborns. METHODS We reviewed Wisconsin screening results for 1994-2008 to identify an ideal panel. RESULTS Upon analyzing approximately 1 million screening results, we found it optimal to use a 23 CFTR mutation panel as a second tier when an immunoreactive trypsinogen (IRT)/DNA algorithm was applied for CF screening. This panel in association with a 96th percentile IRT cutoff gave a sensitivity of 97.3%, but restricting the DNA tier to F508del was associated with 90% (P<.0001). CONCLUSIONS Although CFTR panel selection has been challenging, our data show that a 23 mutation method optimizes sensitivity and is advantageous. The IRT cutoff value, however, is actually more critical than DNA in determining CF newborn screening sensitivity.
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Validation of a high-sensitivity assay for zatebradine in dried blood spots of human blood at pg/ml concentrations using HILIC–MS/MS. Bioanalysis 2010; 2:1863-71. [DOI: 10.4155/bio.10.126] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Background: One of the main reasons for the increased popularity of dried blood spots (DBS) is related to the 3Rs principles (replacement, refinement and reduction) for animal use in drug development. The small blood volume collected using this technique may have a significant impact on the assay sensitivity. An approach that made use of hydrophilic interaction chromatography (HILIC) to enhance the LC–MS assay sensitivity was explored and optimized for a tool compound. Results: A very high-sensitivity assay in dried spots of human blood was validated in the range of 5 to 5000 pg/ml. The use of HILIC increased LC–MS sensitivity up to fivefold compared with other reversed phase chromatographic methods. Conclusion: The good compatibility of the DBS extracts with HILIC and the results of the assay validation for zatebradine at a very low LLOQ demonstrate the high potential and the high performance of this approach.
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Rodrigues R, Magalhaes P, Fernandes M, Gabetta C, Ribeiro A, Pedro K, Valdetaro F, Santos J, Souza RD, Pazin Filho A, Maciel L. Neonatal screening for cystic fibrosis in São Paulo State, Brazil: a pilot study. Braz J Med Biol Res 2009; 42:973-8. [DOI: 10.1590/s0100-879x2009005000017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2008] [Accepted: 07/16/2009] [Indexed: 11/22/2022] Open
Affiliation(s)
| | | | | | | | | | - K.P. Pedro
- Associação de Pais e Amigos dos Excepcionais, Brasil
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Stafler P, Wallis C. Extra corporeal membrane oxygenation (ECMO) therapy in a 3-year-old child with cystic fibrosis: a tale of hope. J R Soc Med 2009; 102 Suppl 1:54-8. [PMID: 19605877 DOI: 10.1258/jrsm.2009.s19012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Castellani C, Southern KW, Brownlee K, Dankert Roelse J, Duff A, Farrell M, Mehta A, Munck A, Pollitt R, Sermet-Gaudelus I, Wilcken B, Ballmann M, Corbetta C, de Monestrol I, Farrell P, Feilcke M, Férec C, Gartner S, Gaskin K, Hammermann J, Kashirskaya N, Loeber G, Macek M, Mehta G, Reiman A, Rizzotti P, Sammon A, Sands D, Smyth A, Sommerburg O, Torresani T, Travert G, Vernooij A, Elborn S. European best practice guidelines for cystic fibrosis neonatal screening. J Cyst Fibros 2009; 8:153-73. [PMID: 19246252 DOI: 10.1016/j.jcf.2009.01.004] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 01/15/2009] [Indexed: 11/27/2022]
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Kloosterboer M, Hoffman G, Rock M, Gershan W, Laxova A, Li Z, Farrell PM. Clarification of laboratory and clinical variables that influence cystic fibrosis newborn screening with initial analysis of immunoreactive trypsinogen. Pediatrics 2009; 123:e338-46. [PMID: 19171585 DOI: 10.1542/peds.2008-1681] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES To ensure that each newborn receives an equitable test of the highest possible sensitivity, we recognized the necessity to reassess immunoreactive trypsinogen and DNA issues in cystic fibrosis newborn screening algorithms. Our objectives included clarification of various factors that influence immunoreactive trypsinogen concentrations and resolution of long-standing questions about variations in immunoreactive trypsinogen levels among newborns. METHODS Immunoreactive trypsinogen data on 660443 newborns who were born between July 1, 1994, and June 30, 2004, were abstracted from the Wisconsin State Laboratory of Hygiene databases and deidentified for analysis. Using a compiled data set, we analyzed various demographic characteristics to determine their role, if any, in immunoreactive trypsinogen variation. Specifically, season of birth, reagent lot, and birth weight were examined. Sensitivities of the most common cystic fibrosis newborn screening protocols, namely immunoreactive trypsinogen/immunoreactive trypsinogen and immunoreactive trypsinogen/DNA, were also investigated. RESULTS Mean and 95th percentile immunoreactive trypsinogen levels were shown to vary by both season and reagent lot number and affect sensitivity of the assay. Low birth weight infants had significantly higher immunoreactive trypsinogen values than normal birth weight infants. Sensitivities were also found to vary on the basis of the algorithm used, with the highest sensitivity of 96.2% calculated for an immunoreactive trypsinogen/DNA protocol with 23 cystic fibrosis transmembrane conductance regulator mutation analyses compared with 80.2% with the immunoreactive trypsinogen/immunoreactive trypsinogen method used in 9 states. CONCLUSIONS Floating, rather than fixed, cutoff values for the initial immunoreactive trypsinogen portion of any cystic fibrosis newborn screening protocol are generally necessary on the basis of the seasonal and reagent lot variations observed. Because of its lower sensitivity, immunoreactive trypsinogen/immunoreactive trypsinogen does not optimize detection of patients with cystic fibrosis.
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Affiliation(s)
- Molly Kloosterboer
- Departments of Population Health Sciences, University of Wisconsin, Madison, WI 53726-2397, USA
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Fingerhut R, Olgemöller B. Newborn screening for inborn errors of metabolism and endocrinopathies: an update. Anal Bioanal Chem 2008; 393:1481-97. [DOI: 10.1007/s00216-008-2505-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Revised: 09/16/2008] [Accepted: 10/16/2008] [Indexed: 11/29/2022]
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Festini F, Taccetti G, Repetto T, Mannini C, Neri S, Bisogni S, de Martino M. Incidence of cystic fibrosis in the Albanian population. Pediatr Pulmonol 2008; 43:1124-1129. [PMID: 18972414 DOI: 10.1002/ppul.20920] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Cystic fibrosis (CF) is the most common life-threatening genetic disease in the Western world. Its incidence varies between 1:4,000 and 1:2,500 among Europeans. No data are available on the incidence of CF among Albanians, mainly due to difficulties of the local health system. GOALS To estimate the incidence of CF and the prevalence of healthy carrier status among Albanian ethnic people; to evaluate the incidence of hypertrypsinaemia at birth among Albanian newborns. METHODS We used the database of the newborn screening of Tuscany, Italy for the period 1991-2005. Children born to both Albanian parents in Tuscany were identified and incidences were calculated. RESULTS The incidence of CF among Albanians (1/555, 99% CI: 1/2,980-1/306) was significantly higher than the rest of the Tuscan population (1/4,101, 99% CI: 1/5,564-1/3,248). The prevalence of CF carrier status among Albanians living in Tuscany is estimated to be 1/12 (99%CI 1/27-1/9) while in the rest of the Tuscan population it is 1/32 (99%CI 1/37-1/28). The incidence of hypertrypsinaemia at birth among Albanian newborns (1/55 99%CI: 1/74-1/44) was significantly higher than in the rest of the population (1/84, 99%CI 1/88-1/82). CONCLUSION The incidence of CF among Albanians is considerably higher than expected. Albanian people have a risk to give birth to children with CF higher than the rest of Europeans. The implementation of a newborn screening program in Albania, together with a CF follow up program is highly advisable.
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Affiliation(s)
- Filippo Festini
- Department of Paediatrics, University of Florence, Florence, Italy
| | | | | | - Claudia Mannini
- Department of Paediatrics, University of Florence, Florence, Italy
| | - Stella Neri
- Department of Paediatrics, University of Florence, Florence, Italy
| | - Sofia Bisogni
- Department of Paediatrics, University of Florence, Florence, Italy
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Hayeems RZ, Bytautas JP, Miller FA. A systematic review of the effects of disclosing carrier results generated through newborn screening. J Genet Couns 2008; 17:538-49. [PMID: 18956236 DOI: 10.1007/s10897-008-9180-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Accepted: 06/24/2008] [Indexed: 11/25/2022]
Abstract
Evidence on the effects of disclosing carrier results identified through newborn screening (NBS) is needed to develop effective strategies for managing these results, and to inform debate about contradictory policies governing genetic testing in minors in the context of NBS relative to clinical care. This is likely to be even more important as technological opportunities for carrier identification through NBS increase. We report the results of a systematic review of evidence related to the generation of carrier results through NBS to summarize what is known about: (1) the outcomes associated with these results; (2) the best strategies for providing information and follow-up care to parents; and (3) the impact they have on reproductive decision-making. Our study expands the existing body of knowledge and identifies gaps in the evidence base. As key players in the management of carrier results clinically, genetic counselors are well positioned to engage in formative research and policy development in this area.
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Affiliation(s)
- R Z Hayeems
- Department of Health Policy Management and Evaluation, University of Toronto, 155 College Street, 4th Floor, Toronto, ON, M5T 3M6, Canada.
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van den Akker-van Marle ME, Dankert HM, Verkerk PH, Dankert-Roelse JE. Cost-effectiveness of 4 neonatal screening strategies for cystic fibrosis. Pediatrics 2006; 118:896-905. [PMID: 16950979 DOI: 10.1542/peds.2005-2782] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES The purpose of this work was to assess the costs of 4 neonatal screening strategies for cystic fibrosis in relation to health effects. In each strategy, the first test was the measurement of serum concentration of immunoreactive trypsin. The second step consisted of either a second immunoreactive trypsin test (strategy 1) or a multiple mutation analysis (strategy 2). In strategies 3 and 4, a third step was added to strategy 2: a second immunoreactive trypsin test (strategy 3) or an extended mutation analysis of the cystic fibrosis gene, that is, a denaturing gradient gel electrophoresis analysis (strategy 4). METHODS We conducted an economic-modeling exercise in the Netherlands based on published data and expert opinions. Subjects were a hypothetical cohort of 200 000 neonates, the approximate number of children born annually in the Netherlands, and we assessed the costs and number of life-years gained as a result of neonatal screening for cystic fibrosis. The costs and effects of changes in reproductive decisions because of neonatal screening were also assessed. RESULTS Immunoreactive trypsin + immunoreactive trypsin had the most favorable cost-effectiveness ratio of 24,800 euro per life-year gained. Immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis achieved more health effects than immunoreactive trypsin + DNA + immunoreactive trypsin at lower cost. The incremental costs per life-year gained of the immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis strategy compared with the immunoreactive trypsin + immunoreactive trypsin strategy were 130,700 euro, whereas the incremental costs of the immunoreactive trypsin + DNA strategy compared with the immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis strategy were 2,154,300 euro. When changes in reproductive decisions as a result of neonatal screening are also taken into account, neonatal screening for cystic fibrosis may lead to financial savings of approximately 1.8 million euro annually, depending on the screening strategy used. CONCLUSIONS Cystic fibrosis screening for neonates is a good economic option, and positive health effects can also be expected. Immunoreactive trypsin + immunoreactive trypsin and immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis are the most cost-effective strategies.
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Massie J, Curnow L, Tzanakos N, Francis I, Robertson CF. Markedly elevated neonatal immunoreactive trypsinogen levels in the absence of cystic fibrosis gene mutations is not an indication for further testing. Arch Dis Child 2006; 91:222-5. [PMID: 16243854 PMCID: PMC2065933 DOI: 10.1136/adc.2005.081349] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To investigate the immunoreactive trypsinogen (IRT) values above the usual 99th centile laboratory cut-off and determine the value of offering further testing to those infants with a markedly elevated IRT but no cystic fibrosis transmembrane regulator (CFTR) gene mutation identified by the screening programme. METHODS All babies born in Victoria, Australia, between 1991 and 2003, were screened by IRT followed by CF gene mutation analysis. RESULTS Of the 806,520 babies born, 9268 with the highest IRT levels had CFTR mutation analysis. There were 123 DeltaF508 homozygotes and 703 heterozygotes (86 with CF, 617 carriers). A total of 8442 babies had no CFTR gene mutation, of whom 18 (0.21%) had CF. The total number of CF babies with IRT greater than the laboratory cut-off was 227 (2.4%). The IRT results of the CF patients were distributed normally, with the majority above the laboratory cut-off of newborn IRT results. There was no evidence of an excess of babies with CF in the very highest levels of IRT above the 99th centile. CONCLUSIONS Only a small proportion of babies with a neonatal IRT >99th centile have CF. Additional CF testing for infants with an elevated IRT but no CFTR gene mutation has an extremely low yield, no matter how high the IRT result.
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Affiliation(s)
- J Massie
- Department of Respiratory Medicine, Royal Children's Hospital, Parkville, Victoria, Australia.
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22
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Steven LC, Gavel G, Young D, Carachi R. Immunoreactive trypsin levels in neonates with meconium ileus. Pediatr Surg Int 2006; 22:236-9. [PMID: 16395608 DOI: 10.1007/s00383-005-1614-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/24/2005] [Indexed: 11/29/2022]
Abstract
Serum immunoreactive trypsin (IRT) is used as a screening test for cystic fibrosis (CF) in neonates in many countries. Variations in IRT levels are observed in healthy and cystic neonates within the first few weeks of life. Fifteen percentage of CF neonates present with meconium ileus (MI). We hypothesised that there may be differences in serum IRT levels in cystic babies with simple and complicated MI. The aim of this study was to investigate the serum levels of IRT in neonates with CF presenting with MI. IRT levels were sequentially measured in neonates (n = 29) with CF with intestinal obstruction due to simple or complicated MI. These were compared to levels obtained from non-cystic neonates/controls admitted with a variety of other intra-abdominal pathologies (n = 49) IRT levels were significantly higher in the CF-MI group than the non-cystic controls (P < 0.001). There was no statistical difference in IRT levels between the simple or complicated MI groups. In the MI group there was no statistical difference between those who required operation, no difference between the pre- and post-operative IRT levels and no significant relationship between IRT levels and birth weight or gestation. Serum IRT levels are significantly elevated in neonates with CF and MI compared with non-cystic, non-MI neonates. The results of this observational study highlight that a single raised level of IRT in a neonate should prompt the analysis for CF regardless of any underlying surgical pathology.
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Affiliation(s)
- L C Steven
- Department of Surgical Paediatrics, Royal Hospital for Sick Children, Dalnair Street, G3 8SJ Glasgow, Scotland
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De Boeck K, Wilschanski M, Castellani C, Taylor C, Cuppens H, Dodge J, Sinaasappel M. Cystic fibrosis: terminology and diagnostic algorithms. Thorax 2005; 61:627-35. [PMID: 16384879 PMCID: PMC2104676 DOI: 10.1136/thx.2005.043539] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
There is great heterogeneity in the clinical manifestations of cystic fibrosis (CF). Some patients may have all the classical manifestations of CF from infancy and have a relatively poor prognosis, while others have much milder or even atypical disease manifestations and still carry mutations on each of the CFTR genes. It is important to distinguish between these categories of patients. The European Diagnostic Working Group proposes the following terminology. Patients are diagnosed with classic or typical CF if they have one or more phenotypic characteristics and a sweat chloride concentration of >60 mmol/l. The vast majority of CF patients fall into this category. Usually one established mutation causing CF can be identified on each CFTR gene. Patients with classic CF can have exocrine pancreatic insufficiency or pancreatic sufficiency. The disease can have a severe course with rapid progression of symptoms or a milder course with very little deterioration over time. Patients with non-classic or atypical CF have a CF phenotype in at least one organ system and a normal (<30 mmol/l) or borderline (30-60 mmol/l) sweat chloride level. In these patients confirmation of the diagnosis of CF requires detection of one disease causing mutation on each CFTR gene or direct quantification of CFTR dysfunction by nasal potential difference measurement. Non-classic CF includes patients with multiorgan or single organ involvement. Most of these patients have exocrine pancreatic sufficiency and milder lung disease. Algorithms for a structured diagnostic process are proposed.
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Affiliation(s)
- K De Boeck
- Department of Pediatrics, Pediatric Pulmonology, University Hospital of Leuven, Herestraat 49, 3000 Leuven, Belgium.
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Massie J, Clements B. Diagnosis of cystic fibrosis after newborn screening: the Australasian experience--twenty years and five million babies later: a consensus statement from the Australasian Paediatric Respiratory Group. Pediatr Pulmonol 2005; 39:440-6. [PMID: 15704202 DOI: 10.1002/ppul.20191] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Newborn screening for cystic fibrosis has been used in Australia and New Zealand for over 20 years. In that time, considerable experience has been developed regarding the early diagnosis of cystic fibrosis after newborn screening. To date, there has not been a consensus on the process of screening and clinical evaluation leading to the diagnosis of cystic fibrosis in infants, many of whom are not symptomatic at time of notification of the screening result. The aim of this paper is to provide some consensus on the important issues of a cystic fibrosis diagnosis arising from newborn screening, based on the experience gained in Australia and New Zealand over the last 20 years.
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Affiliation(s)
- John Massie
- Department of Respiratory Medicine, Murdoch Children's Research Institute and University of Melbourne Royal Children's Hospital, Melbourne, Australia.
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Kösel S, Burggraf S, Fingerhut R, Dörr HG, Roscher AA, Olgemöller B. Rapid second-tier molecular genetic analysis for congenital adrenal hyperplasia attributable to steroid 21-hydroxylase deficiency. Clin Chem 2004; 51:298-304. [PMID: 15608154 DOI: 10.1373/clinchem.2004.042416] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Neonatal screening for steroid 21-hydroxylase (CYP21) deficiency is performed to identify congenital adrenal hyperplasia (CAH). The immunologic assay for 17alpha-hydroxyprogesterone (17-OHP) has a high rate of false positives. We assessed the potential for increasing the specificity for CAH by use of a second step involving analysis of the CYP21 gene. METHODS Between January 1999 and December 2003, a total of 810,000 newborns were screened. Of these, 7920 had to be retested because their 17-OHP values were above the cutoff of the assay. Sixty-one had positive 17-OHP values in their recall samples and were diagnosed as having CAH. We used a rapid assay for common mutations of the CYP21 gene to analyze these 61 samples. In a prospective study, 198 consecutive samples that had increased 17-OHP and 100 samples that had normal 17-OHP concentrations were genotyped. RESULTS Fifty-nine of 61 cases diagnosed as having CAH were confirmed genetically as CYP21 deficiencies. One patient had a 3beta-hydroxysteroid dehydrogenase deficiency, and one patient carried no CYP21 mutations. The 198 increased 17-OHP results were designated as false positives after immunologic testing of recall samples. None of these samples exhibited the genetic pattern consistent with CYP21 deficiency. CONCLUSIONS If samples with increased 17-OHP values were screened genetically, the number of retests would decrease by approximately 90%, but the overall sensitivity of CAH screening would remain the same. Adding a second-tier genetic step would require a modest increase in costs, but is counterbalanced by fewer recalls, less clinical follow-up, and a reduction in unnecessary worry for families.
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Abstract
An efficient newborn screening test for detecting cystic fibrosis has been available for over 20 years but is only now coming into widespread use. Blood immunoreactive trypsin is elevated in babies with cystic fibrosis and its measurement in dried blood spots is the primary screening tool. Poor discrimination in the first week requires a re-sampling step. The identification of the cystic fibrosis transmembrane conductance regulator gene and the discovery of a common mutation has allowed a combination of the primary screening test with a DNA test using the same sample. Differing genetic backgrounds have led to the development of population-specific protocols. A false-negative rate of around 5% is usual. Specificity is high. In all protocols involving a DNA test, confirmation of the diagnosis by sweat test is necessary when only one mutation is identified, identification of some carriers therefore being unavoidable. Careful counselling is needed for the families of these carriers.
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Affiliation(s)
- Bridget Wilcken
- New South Wales Newborn Screening Programme, The Children's Hospital at Westmead, Sydney, Australia.
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Abstract
We review the current situation with respect to newborn cystic fibrosis screening (NCFS) across the world. The challenges of establishing an NCFS programme are reflected in the diversity of those programmes identified. All employ an initial immunoreactive trypsinogen (IRT) measurement during the first week of life. If this is positive, a second IRT analysis at 4 weeks of age improves the specificity of the test; most programmes have, however, moved to DNA analysis at this point, which improves their sensitivity. Incorporating DNA analysis results in the identification of carriers, which may have implications for families but is generally considered positive. Some programmes have incorporated a second IRT test as well as DNA analysis, either to increase the sensitivity of the test in an area with a low DeltaF508 frequency or to reduce the number of infants requiring a sweat test. Whichever algorithm is selected, the implementation of a successful programme relies on clear pathways and good information for parents.
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Affiliation(s)
- Kevin W Southern
- Institute of Child Health, University of Liverpool, Royal Liverpool Children's Hospital, Alder Hey, Liverpool L12 2AP, UK.
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29
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Affiliation(s)
- M Super
- Royal Manchester Children's Hospital, Manchester M27 4HA, UK.
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30
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Lee DS, Rosenberg MA, Peterson A, Makholm L, Hoffman G, Laessig RH, Farrell PM. Analysis of the costs of diagnosing cystic fibrosis with a newborn screening program. J Pediatr 2003; 142:617-23. [PMID: 12838188 DOI: 10.1067/mpd.2003.209] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES To compare the cost of diagnosing cystic fibrosis (CF) through a newborn screening program with the traditional method and to estimate the cost of CF diagnosis if a national newborn screening program is implemented. STUDY DESIGN Surveys were conducted to determine the annual number of sweat tests in 1991 and in 2000 after implementation of statewide screening. A national survey of sweat test costs was used to estimate the annual expense for diagnosing CF in the United States through newborn screening. RESULTS Since the introduction of newborn screening for CF, the numbers of sweat tests ordered annually have decreased from 1670 to 804 (including 134 follow-up tests from screening). The current estimated annual cost of Wisconsin CF newborn screening and diagnosis is $4.58 per newborn infant. The estimated annual cost per newly diagnosed CF infant using the traditional method is $4.97 per newborn infant. If no additional sweat tests were ordered outside of the newborn screening program, the estimated annual cost of a Wisconsin CF newborn screening and diagnosis is $2.66 per newborn and $2.47 per newborn for a national CF newborn screening program. CONCLUSIONS A CF newborn screening program provides a potentially cost-saving alternative to the traditional method of diagnosis of CF.
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Affiliation(s)
- Don S Lee
- University of Wisconsin, Madison, Wisconsin, USA
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31
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Galvin-Parton PA. Screening for GALC to make neonatal diagnosis and initial neonatal stem cell treatment with umbilical cord blood. Pediatr Transplant 2003; 7:83-5. [PMID: 12654046 DOI: 10.1034/j.1399-3046.2003.00032.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Krone N, Braun A, Weinert S, Peter M, Roscher AA, Partsch CJ, Sippell WG. Multiplex Minisequencing of the 21-Hydroxylase Gene as a Rapid Strategy to Confirm Congenital Adrenal Hyperplasia. Clin Chem 2002. [DOI: 10.1093/clinchem/48.6.818] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Background: Congenital adrenal hyperplasia (CAH) is a frequent autosomal recessive disease, with a wide range of clinical manifestations, most commonly attributable to mutations in the 21-hydroxylase gene (CYP21). Large gene deletions, large gene conversions, a small 8-basepair deletion, and eight point mutations in CYP21 account for ∼95% of all enzyme deficiencies. We developed a new strategy for a rapid CYP21 analysis.
Methods: DNA samples from 40 CAH patients previously genotyped by direct DNA sequencing were reanalyzed by allele-specific amplification of the functional CYP21 gene followed by a multiplex minisequencing reaction using 13 primers. In addition, a second PCR that amplified a part of exon 3 was used to demonstrate the presence or absence of at least one functional gene.
Results: The assay detected the P453S mutation and nine of the most common mutations (P30L, intron 2 splice, Δ8bp, I172N, exon 6 cluster, V281L, F306+t, Q318X, and R356W) caused by microconversions from the CYP21P pseudogene. The concordance was 100% for detecting these mutations, including gene deletions and large gene conversions. The 40 patient DNA samples were analyzed in 1.5 working days by one technician (actual hands-on time, 3.5 h). The material cost for analyzing one sample was approximately €10.00 (US $9.00).
Conclusions: This novel mutation screening strategy rapidly detects 90–95% of all mutations associated with CAH and appears applicable as a tool for confirmation of increased 17-hydroxyprogesterone found in neonatal CAH screening.
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Affiliation(s)
- Nils Krone
- Laboratory of Molecular Endocrinology, Division of Pediatric Endocrinology, Department of Pediatrics, Universitätsklinikum Kiel, Schwanenweg 20, D-24105 Kiel, Germany
| | - Andreas Braun
- Sequenom Inc., 3595 John Hopkins Court, San Diego, CA 92121-1331
| | - Stefanie Weinert
- Laboratory of Molecular Endocrinology, Division of Pediatric Endocrinology, Department of Pediatrics, Universitätsklinikum Kiel, Schwanenweg 20, D-24105 Kiel, Germany
| | - Michael Peter
- Laboratory of Molecular Endocrinology, Division of Pediatric Endocrinology, Department of Pediatrics, Universitätsklinikum Kiel, Schwanenweg 20, D-24105 Kiel, Germany
| | - Adelbert A Roscher
- Department of Clinical Chemistry, Metabolics and Molecular Genetics, University Children’s Hospital, Ludwig-Maximilians-Universität, München, Lindwurmstrasse 4, D-80337 Munich, Germany
| | - Carl-Joachim Partsch
- Laboratory of Molecular Endocrinology, Division of Pediatric Endocrinology, Department of Pediatrics, Universitätsklinikum Kiel, Schwanenweg 20, D-24105 Kiel, Germany
| | - Wolfgang G Sippell
- Laboratory of Molecular Endocrinology, Division of Pediatric Endocrinology, Department of Pediatrics, Universitätsklinikum Kiel, Schwanenweg 20, D-24105 Kiel, Germany
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Abstract
Mandated newborn screening programs for genetic and other congenital conditions for the some 4 million infants born in the United States each year have seen dramatic changes over the past decade. With the mapping of the human genome and other advances in science and technology, there will be continued challenges to and changes in these programs. Nurses who care for infants and their families should be knowledgeable about those changes to correctly transmit information to families and to participate in determining policy for newborn screening practices.
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Affiliation(s)
- Michele A Lloyd-Puryear
- Genetic Services Branch, Division of Services for Children With Health Needs, Maternal and Child Health Bureau, Health Resources and Services Administration, US Department of Health and Human Services, Rockville, MD 20857, USA.
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Abstract
Screening of newborn infants for genetic disease began over 35 years ago as a public health measure to prevent mental retardation in phenylketonuria (PKU). It was so successful that tests for several other genetic disorders were added. We review the current status of this screening, including discussions of the genetic disorders often covered and the results of newborn screening for them. We emphasize recent advances. These include expansion of coverage for genetic disorders with the new methodology of tandem mass spectrometry (MS-MS) and the introduction of molecular (DNA) testing to increase the specificity of testing for several disorders, thereby reducing false-positive rates. These and other advances have also produced issues of criteria for screening, missed cases, and appropriate use of stored newborn specimens.
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Affiliation(s)
- H L Levy
- Genetic Service, Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.
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Young SS, Kharrazi M, Pearl M, Cunningham G. Cystic fibrosis screening in newborns: results from existing programs. Curr Opin Pulm Med 2001; 7:427-33. [PMID: 11706321 DOI: 10.1097/00063198-200111000-00012] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Newborn screening for cystic fibrosis (CF) provides early identification and initiation of treatment to infants with this fatal and often misdiagnosed genetic disease. Although reports of health benefits continue to mount from decade-old screening programs in Wisconsin, France, and Australia, newborn screening for CF is still a highly debated topic in genetic policy development. This article summarizes the literature published between May 2000 and April 2001 regarding the health benefits, risks, cost-effectiveness, and programmatic issues of newborn screening for CF. The literature consistently shows evidence of benefits and lack of harm from newborn screening for CF.
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Affiliation(s)
- S S Young
- Sequoia Foundation, La Jolla, California, USA
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Massie RJ, Poplawski N, Wilcken B, Goldblatt J, Byrnes C, Robertson C. Intron-8 polythymidine sequence in Australasian individuals with CF mutations R117H and R117C. Eur Respir J 2001; 17:1195-200. [PMID: 11491164 DOI: 10.1183/09031936.01.00057001] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Compound heterozygotes for a severe cystic fibrosis transmembrane conductance regulator (CFTR) mutation and the R117H or R117C mutation (R117H/C) have clinical presentations that vary from classic cystic fibrosis (CF) to an incidental genetic finding. The aim of this study was to assess the influence of the intron-8 polythvmidine sequence (IVS8) on the relationship between genotype and phenotype of individuals with R117H/C. All individuals with R117H/C known to CF clinics in Australia and New Zealand were retrospectively studied by collecting information on genotype, age, pancreatic status, sweat electrolytes, sputum microbiology and pulmonary function. Forty-one individuals (39 with R117H and two with R117C), 16 on an IVS8-5T background and 25 on an IVS8-7T background were identified. Twelve individuals presented clinically, four were siblings of known R117H/C compound heterozygotes and 25 were detected by newborn screening. Eleven of 14 of the IVS8-5T group (78%) with sweat chloride results available had sweat CI > 60 mmol x L(-1) compared to 5 (20%) of the R117H/7T group (Chi-squared=10.4, p=0.001). Two were pancreatic insufficient, both IVS8-5T. Two IVS8-5T individuals have recently died (aged 43 and 19) and of the 14 surviving IVS8-5T group, 11 (79%) are symptomatic compared to eight (32%) of the IVS8-7T individuals (Chi-squared=6.1, p=0.01). In conclusion, most individuals with R117H/C on a IVS8-5T background have an elevated sweat chloride and clinical cystic fibrosis, which in some cases is severe. Most individuals with R117H/C on an IVS8-7T background do not have clinical cystic fibrosis but should be followed for the development of clinical disease.
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Affiliation(s)
- R J Massie
- Dept of Respiratory Medicine, Royal Children's Hospital, Melbourne, Australia
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37
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Scotet V, De Braekeleer M, Audrézet MP, Lodé L, Verlingue C, Quéré I, Mercier B, Duguépéroux I, Codet JP, Moineau MP, Parent P, Férec C. Prevalence of CFTR mutations in hypertrypsinaemia detected through neonatal screening for cystic fibrosis. Clin Genet 2001; 59:42-7. [PMID: 11168024 DOI: 10.1034/j.1399-0004.2001.590107.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Nowadays, most of the neonatal screening programs for cystic fibrosis (CF) combine the assay of immunoreactive trypsinogen (IRT) with the analysis of the most common mutations of the CFTR gene. The efficiency of this strategy is now well established, but the identification of heterozygotes among neonates with increased IRT is perceived as a drawback. We proposed to assess the heterozygosity frequency among the children with hypertrypsinaemia detected through the CF screening program implemented in Brittany (France) 10 years ago, to describe the CFTR mutations detected in them and to determine the frequency of the IVS8-5T variant. The molecular analysis relies, in our protocol, on the systematic analysis of three exons of the gene (7-10-11). A total of 160,019 babies were screened for CF in western Brittany between 1992 and 1998. Of the 1964 newborns with increased IRT (1.2%), 60 were CF and 213 were carriers. Heterozygosity frequency was 12.8%), i.e. 3 times greater than in the general population (3.9%; p < 10(-6)), Variability of mutations detected in carriers was greater than in CF children (21 mutations versus 10) and a high proportion of mild mutations or variants (A349V, R297Q, R347H, V317A, G544S, R553G, etc) was observed in carriers. The allelic frequency of the 5T (5.6%) was not significantly increased in this cohort. This study is consistent with previous ones in finding a significantly higher rate of heterozygotes than expected among neonates with hypertrypsinaemia. The strategy of screening used here allows to highlight the variability of mutations detected in heterozygotes and to show that severe mutations, as well as mild mutations, have been observed in neonates with hypertrypsinaemia. If there is no doubt that neonatal hypertrypsinaemia is associated with an elevated frequency of carriers, the underlying mechanisms remain obscure.
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Affiliation(s)
- V Scotet
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité CHU Morvan, UBO, Brest, France
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Scotet V, de Braekeleer M, Roussey M, Rault G, Parent P, Dagorne M, Journel H, Lemoigne A, Codet JP, Catheline M, David V, Chaventré A, Duguépéroux I, Verlingue C, Quéré I, Mercier B, Audrézet MP, Férec C. Neonatal screening for cystic fibrosis in Brittany, France: assessment of 10 years' experience and impact on prenatal diagnosis. Lancet 2000; 356:789-94. [PMID: 11022925 DOI: 10.1016/s0140-6736(00)02652-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Neonatal screening for cystic fibrosis has been a subject of debate over the past few years. This study assesses 10 years of neonatal screening in Brittany, France, and examines its impact on prenatal screening of subsequent pregnancies in couples with an affected child. METHODS The study included all the neonates screened for cystic fibrosis in Brittany from Jan 1, 1989, to Dec 31, 1998. The screening consisted of an immunoreactive trypsinogen assay from dried blood spots, plus, from 1993, mutation analysis. Data were collected on incidence of cystic fibrosis, and genotypic and biochemical characteristics. The use of prenatal screening of subsequent pregnancies in affected families was also investigated. FINDINGS Of the 343,756 neonates screened, 118 children with cystic fibrosis were identified, giving an incidence of one in 2913. All mutated alleles were characterised: 34 different mutations resulting in 36 genotypes were detected. The introduction of DNA analysis into the protocol greatly reduced the recall rate and increased the sensitivity of the test. The mean cost of the screening programme was US$2.32 per screened child. 39 (34%) of the families identified by neonatal screening opted for subsequent prenatal diagnosis at least once. 12 couples would have benefited from this procedure while their first child was still symptom-free. 42 healthy children were born, and 18 pregnancies were terminated (therapeutic abortion rate of 100%). INTERPRETATION We have shown the feasibility of neonatal screening for cystic fibrosis in Brittany. Through the detection of a large range of mutations, neonatal screening provides the opportunity for more reliable prenatal diagnosis and cascade screening. The neonatal screening programme described here could provide a good model for other countries intending to initiate such a scheme.
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Affiliation(s)
- V Scotet
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, CHU Morvan, UBO, EFS-Bretagne, Brest, France
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39
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Massie RJ, Olsen M, Glazner J, Robertson CF, Francis I. Newborn screening for cystic fibrosis in Victoria: 10 years' experience (1989-1998). Med J Aust 2000; 172:584-7. [PMID: 10914103 DOI: 10.5694/j.1326-5377.2000.tb124123.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To review the effectiveness of statewide newborn screening for cystic fibrosis (CF) in Victoria over the first 10 years of the program (1989-1998). DESIGN Population study involving screening of newborns by immunoreactive trypsinogen (IRT) testing on Day 3-5, followed by either repeat IRT testing (1989-1990) or delta F508 mutation analysis (1991-1998). PATIENTS AND SETTING All babies screened for CF in a newborn screening program in Victoria in 1989-1998. MAIN OUTCOME MEASURE The diagnosis of CF. RESULTS Of 635,157 babies born in Victoria in the 10 years, 191 were diagnosed with CF. A further 30 cases were detected antenatally, giving an incidence of 1/2874 (95% CI, 1/2519-1/3294). CF was detected early in 182 babies (95.3% of affected babies in the screened cohort)--136 by screening, 35 because they had meconium ileus, and 11 because they were siblings of older children with CF. Nine cases of CF were missed by screening. Of these nine babies, four did not have an elevated neonatal IRT level, one had a normal IRT level at repeat testing at 4-6 weeks (1989-1990), three did not have a delta F508 mutation (1991-1998), and one had a false negative sweat test result. Six of the nine missed babies (67%) were diagnosed within four months of birth. CONCLUSION Newborn screening for CF in Victoria has proven effective in detecting most babies with CF in the newborn period. However, a sweat test should be requested when the clinical features suggest the diagnosis of CF, even if the child has been screened.
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Affiliation(s)
- R J Massie
- Department of Respiratory Medicine, Royal Children's Hospital, Melbourne, Vic.
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40
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Schaedel C, Hjelte L, de Monestrol I, Johannesson M, Kollberg H, Kornfält R, Holmberg L. Three common CFTR mutations should be included in a neonatal screening programme for cystic fibrosis in Sweden. Clin Genet 1999; 56:318-22. [PMID: 10636451 DOI: 10.1034/j.1399-0004.1999.560410.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Children with cystic fibrosis (CF) diagnosed by neonatal screening have a better nutritional development and other advantages compared with those in a nonscreened group. The two-tier immunoreactive trypsinogen (IRT)/DNA screening protocol has been found superior to the single-tier IRT approach, improving the positive predictive value and thus reducing the false-positive rate. However, variations of the DNA test are required for different populations. In this study we examined CFTR (cystic fibrosis transmembrane conductance regulator) mutations in 331 CF patients attending the centres in Stockholm, Lund and Uppsala, comprising about 75% of the CF population in Sweden. The frequency of deltaF508 among CF alleles was 68.3%. There were two other mutations, 394delTT and 3659delC, found to be fairly frequent, amounting to 8.5 and 7.9%, respectively. Other mutations were comparatively rare. A simple and effective method of analysing the three mutations from Guthrie cards has been developed. Assuming Hardy-Weinberg equilibrium, 90% of our CF patients will be expected to carry at least one deltaF508 allele and 97.6% to carry at least one deltaF508, 394delTT or 3659delC copy. Including the latter two in a screening programme would thus substantially reduce the risk of a false-negative outcome.
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Affiliation(s)
- C Schaedel
- Department of Paediatrics, University Hospitals, Lund, Sweden.
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41
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Waters DL, Wilcken B, Irwing L, Van Asperen P, Mellis C, Simpson JM, Brown J, Gaskin KJ. Clinical outcomes of newborn screening for cystic fibrosis. Arch Dis Child Fetal Neonatal Ed 1999; 80:F1-7. [PMID: 10325803 PMCID: PMC1720879 DOI: 10.1136/fn.80.1.f1] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To determine how early diagnosis of cystic fibrosis, using neonatal screening, affects long term clinical outcome. METHODS Fifty seven children with cystic fibrosis born before neonatal screening was introduced (1978 to mid 1981) and a further 60 children born during the first three years of the programme (mid 1981 to 1984), were followed up to the age of 10. The cohorts were compared on measures of clinical outcome, including height, weight, lung function tests, chest x-ray picture and Shwachman score. RESULTS Age and sex adjusted standard deviation scores (SDS) for height and weight were consistently higher in children screened for cystic fibrosis than in those born before screening. At 10 years of age, average differences in SDS between groups were 0.4 (95% CI -0.1, 0.8) for weight and 0.3 (95% CI -0.1, 0.7) for height. This translates to an average difference of about 2.7 cm in height and 1.7 kg in weight. Mean FEV1 and FVC (as percentage predicted) were significantly higher in the screened cohort at 5 and 10 years of age, with an average difference of 9.4% FEV1 (95% CI 0.8, 17.9) and 8.4% FVC (95% CI 1.8, 15.0) at 10 years. Chest x-ray scores were not different between the groups at any age, but by 10 years screened patients scored an average 5.3 (95% CI 1.2, 9.4) points higher on the Shwachman score. CONCLUSION Although not a randomised trial, this long term observational study indicates that early treatment made possible by neonatal screening may be important in determining subsequent clinical outcomes for children with cystic fibrosis. For countries contemplating the introduction of neonatal screening for cystic fibrosis, its introduction to some areas in a cluster randomised design will permit validation of studies performed to date.
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Affiliation(s)
- D L Waters
- James Fairfax Institute of Paediatric Nutrition, Royal Alexandra Hospital for Children, Sydney, New South Wales, Australia
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42
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Hua CT, Hopwood JJ, Carlsson SR, Harris RJ, Meikle PJ. Evaluation of the lysosome-associated membrane protein LAMP-2 as a marker for lysosomal storage disorders. Clin Chem 1998. [DOI: 10.1093/clinchem/44.10.2094] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AbstractFor many lysosomal storage disorders, presymptomatic detection, before the onset of irreversible pathology, will greatly improve the efficacy of current and proposed therapies. In the absence of a family history, presymptomatic detection can be achieved only by a comprehensive newborn screening program. Recently we reported that the lysosome-associated membrane protein LAMP-1 was increased in the plasma from ∼70% of individuals with lysosomal storage disorders. Here we report on the evaluation of a second lysosome-associated membrane protein, LAMP-2, as a marker for this group of disorders. The median concentration of LAMP-2 in the plasma of healthy individuals was 1.21 mg/L, fourfold higher than the median LAMP-1 concentration (0.31 mg/L). LAMP-2 was increased in >66% of patients with lysosomal storage disorders, and the increases coincided with increased LAMP-1 concentrations. The reference intervals for LAMP-1 and LAMP-2 in blood spots taken from newborns were 0.20–0.54 mg/L (n = 1600) and 0.95–3.06 mg/L (n = 1600), respectively. A high correlation was observed between the concentrations of LAMP-1 and LAMP-2 in both control and affected individuals. The higher concentrations of LAMP-2, relative to LAMP-1, in plasma make LAMP-2 an attractive marker; however, the final selection will be dependent on the availability of new diagnostic markers and their ability to detect disorders currently not identified by LAMP-2.
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Affiliation(s)
- Chi T Hua
- Lysosomal Diseases Research Unit, Department of Chemical Pathology, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, South Australia 5006, Australia
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia 5000, Australia
| | - John J Hopwood
- Lysosomal Diseases Research Unit, Department of Chemical Pathology, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, South Australia 5006, Australia
| | - Sven R Carlsson
- Department of Medical Biochemistry and Biophysics, Umea University, Umea S-901 87, Sweden
| | - Ray J Harris
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia 5000, Australia
| | - Peter J Meikle
- Lysosomal Diseases Research Unit, Department of Chemical Pathology, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, South Australia 5006, Australia
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Abstract
Cystic fibrosis (CF) should be considered in patients with a wide variety of clinical presentations and of diverse racial and ethnic backgrounds. In most cases the diagnosis is suggested by manifestations of chronic sinopulmonary disease and exocrine pancreatic insufficiency, and then confirmed by a positive sweat test result. Patients may, however, present with pancreatic sufficiency or other atypical clinical features, sometimes in association with normal or borderline sweat test results. In such cases, the ability to detect CF mutations and to measure transepithelial bioelectric properties can be diagnostically useful. Mutation analysis can also be used for carrier screening, prenatal diagnosis, and newborn screening.
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Affiliation(s)
- B J Rosenstein
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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44
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Poyser KH, Wyatt HA, Chambers SM. Multiplex genotyping for cystic fibrosis from filter paper blood spots. Ann Clin Biochem 1998; 35 ( Pt 5):611-5. [PMID: 9768326 DOI: 10.1177/000456329803500503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cystic fibrosis is a common disease of the Caucasian population and is associated with significant early mortality. We present a simple and rapid method for cystic fibrosis genotyping from filter paper blood spots, using a currently available commercial genotyping kit. Using multiplex technology, genotype information on the four most common UK mutations can easily be obtained within a single working day. Used in conjunction with current immunoreactive typsinogen screening protocols, blood spot genotyping offers a method of hastening the diagnosis, and thus treatment, of cystic fibrosis.
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Affiliation(s)
- K H Poyser
- Department of Clinical Biochemistry, King's College Hospital, Denmark Hill, London, UK
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Wildhagen MF, Hilderink HB, Verzijl JG, Verheij JB, Kooij L, Tijmstra T, ten Kate LP, Habbema JD. Costs, effects, and savings of screening for cystic fibrosis gene carriers. J Epidemiol Community Health 1998; 52:459-67. [PMID: 9799881 PMCID: PMC1756730 DOI: 10.1136/jech.52.7.459] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
STUDY OBJECTIVE Evaluating the costs, effects, and savings of several strategies for cystic fibrosis (CF) gene carrier screening. DESIGN A general model for evaluating prenatal, preconceptional, school, and neonatal carrier screening was constructed. For prenatal and preconceptional screening, two strategies were evaluated: single entry and double entry two step couple screening. Firstly, the Dutch situation was evaluated prospectively; subsequently the results were generalised to other carrier frequencies. SETTING Prospective simulation model. MAIN RESULTS Of all screening strategies, neonatal carrier screening gives most carrier couples an informed choice concerning reproduction. If the parents of carrier newborns would not be tested however, prenatal screening detects most carrier couples. Prenatal and single entry preconceptional screening programmes have a favourable cost-savings balance in the Netherlands under a wide range of assumptions. For double entry preconceptional screening and neonatal screening, high enough values of uptake of screening, prenatal diagnosis, and induced abortion are necessary. School carrier screening does not have a favourable cost-savings balance. CONCLUSIONS If a CF screening programme is judged to be useful on individual and social grounds, costs considerations are no obstacle for prenatal and single entry preconceptional screening.
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Affiliation(s)
- M F Wildhagen
- Department of Public Health, Erasmus University Rotterdam, The Netherlands
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Mischler EH, Wilfond BS, Fost N, Laxova A, Reiser C, Sauer CM, Makholm LM, Shen G, Feenan L, McCarthy C, Farrell PM. Cystic fibrosis newborn screening: impact on reproductive behavior and implications for genetic counseling. Pediatrics 1998; 102:44-52. [PMID: 9651412 DOI: 10.1542/peds.102.1.44] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To evaluate the impact of newborn screening for cystic fibrosis (CF) on the reproductive knowledge and behavior of CF families and to determine if heterozygote detection with the immunoreactive trypsinogen (IRT) method in conjunction with DNA analysis (IRT/DNA) influences knowledge and attitudes about reproduction in false-positive families. METHODS The Wisconsin CF Neonatal Screening Project investigated 650 340 infants from 1985 to 1994 in a comprehensive randomized controlled trial to study both benefits and risks of newborn screening and to determine if early diagnosis would improve the prognosis of children with CF. Assessments of reproductive knowledge, attitudes, and behaviors of 135 families of children diagnosed as having CF in both the early treatment group and control groups were made 3 months after diagnosis using a questionnaire which was completed by 100 families. The same questionnaire was administered 1 year later to evaluate retention of information. It was completed by 71 families. A follow-up assessment tool was also administered in 1994 and responses obtained from 73 families. Knowledge, attitudes, and behavior among false-positive families were also assessed at the time of the sweat test in 206 families who experienced IRT screening and 109 families tested with the IRT/DNA method. Follow-up assessments were completed 1 year later in 106 IRT families and 63 IRT/DNA families. RESULTS In families with a CF child, 95% initially understood that there was a 1 in 4 risk in subsequent pregnancies, and there was good retention of this information 1 year later. At the 1994 assessment, 52% of families had not yet conceived more children, but 74% of these already had children. In the couples in whom CF was diagnosed in the first child, 70% (95% confidence interval = 54% to 85%) conceived more children. There were 43 subsequent pregnancies in 31 families. Prenatal diagnosis was used by 26% of the families (8/31) for 21% of the pregnancies (9/43). There were 3 pregnancies with CF detected, all of which were carried to term. In the false-positive groups, >95% of families initially understood that their child definitely did not have CF. There was no difference between false-positive IRT and IRT/DNA groups, and the information was retained at 1 year. Follow-up assessment 1 year after negative sweat tests revealed that 7% of the IRT and 10% of the IRT/DNA families still thought about the results often or constantly. When asked whether the experience of screening affected feelings about having more children, an affirmative response was obtained in 4% of IRT families but in 17% of IRT/DNA families. One year later, more than half of the false-positive IRT/DNA families did not understand that they were at increased risk of having a child with CF. CONCLUSIONS We conclude that CF neonatal screening does not have a significant impact on the reproductive behavior of most families and that prenatal diagnosis is not used by the majority of CF families. IRT/DNA testing experiences seem to affect attitudes about having more children, and some parents are confused about the implications of the results, even with genetic counseling. However, persistent concerns about the sweat test result are limited. Questions raised by this study confirm the need for more research regarding the process of genetic counseling and its impact on reproductive attitudes and behavior in the newborn screening setting.
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Affiliation(s)
- E H Mischler
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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47
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Cunningham S, Marshall T. Influence of five years of antenatal screening on the paediatric cystic fibrosis population in one region. Arch Dis Child 1998; 78:345-8. [PMID: 9623398 PMCID: PMC1717529 DOI: 10.1136/adc.78.4.345] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Antenatal screening for cystic fibrosis has been endorsed by the US National Institutes of Health. Edinburgh is the only city in the UK with an established routine antenatal screening programme for cystic fibrosis. AIMS To report the change in numbers of infants diagnosed with cystic fibrosis born in Edinburgh after the introduction of antenatal screening for the disease. POPULATION Infants diagnosed as having cystic fibrosis (by sweat test or genotyping, or both) in the seven years before antenatal testing (1984-90) and the first five years of antenatal testing (1991-95). Children born in this region who had moved before diagnosis were identified from the UK cystic fibrosis survey database. RESULTS The incidence of cystic fibrosis decreased from an average of 4.6 to 1.6 children each year with antenatal screening. The reduction in the incidence (65%) was greater than that accounted for by prenatal diagnosis and termination (36%). Of the eight children born with cystic fibrosis during the period of antenatal screening, five had been subject to antenatal screening: three had only one mutation identified, one was missed due to a laboratory error, and one was identified as a one in four risk, but prenatal diagnosis was not performed. CONCLUSIONS Antenatal testing for cystic fibrosis has successfully reduced the incidence of cystic fibrosis in this region. Although the numbers are small, it is possible that the reduction in numbers may have been greater than might be expected from antenatal screening alone.
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Affiliation(s)
- S Cunningham
- Department of Child Life and Health, University of Edinburgh
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49
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Wierzbicki AS. Laboratory investigations by DNA amplification: from research to practice. Ann Clin Biochem 1998; 35 ( Pt 1):5-11. [PMID: 9463735 DOI: 10.1177/000456329803500102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- A S Wierzbicki
- United Medical School of Guy's, St Thomas' Hospital, London, UK
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50
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Gregg RG, Simantel A, Farrell PM, Koscik R, Kosorok MR, Laxova A, Laessig R, Hoffman G, Hassemer D, Mischler EH, Splaingard M. Newborn screening for cystic fibrosis in Wisconsin: comparison of biochemical and molecular methods. Pediatrics 1997; 99:819-24. [PMID: 9164776 DOI: 10.1542/peds.99.6.819] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVES To evaluate neonatal screening for cystic fibrosis (CF), including study of the screening procedures and characteristics of false-positive infants, over the past 10 years in Wisconsin. An important objective evolving from the original design has been to compare use of a single-tier immunoreactive trypsinogen (IRT) screening method with that of a two-tier method using IRT and analyses of samples for the most common cystic fibrosis transmembrane regulator (CFTR) (DeltaF508) mutation. We also examined the benefit of including up to 10 additional CFTR mutations in the screening protocol. METHODS From 1985 to 1994, using either the IRT or IRT/DNA protocol, 220 862 and 104 308 neonates, respectively, were screened for CF. For the IRT protocol, neonates with an IRT >/=180 ng/mL were considered positive, and the standard sweat chloride test was administered to determine CF status. For the IRT/DNA protocol, samples from the original dried-blood specimen on the Guthrie card of neonates with an IRT >/=110 ng/mL were tested for the presence of the DeltaF508 CFTR allele, and if the DNA test revealed one or two DeltaF508 alleles, a sweat test was obtained. RESULTS Both screening procedures had very high specificity. The sensitivity tended to be higher with the IRT/DNA protocol, but the differences were not statistically significant. The positive predictive value of the IRT/DNA screening protocol was 15.2% compared with 6.4% if the same samples had been screened by the IRT method. Assessment of the false-positive IRT/DNA population revealed that the two-tier method eliminates the disproportionate number of infants with low Apgar scores and also the high prevalence of African-Americans identified previously in our study of newborns with high IRT levels. We found that 55% of DNA-positive CF infants were homozygous for DeltaF508 and 40% had one DeltaF508 allele. Adding analyses for 10 more CFTR mutations has only a small effect on the sensitivity but is likely to add significantly to the cost of screening. CONCLUSIONS Advantages of the IRT/DNA protocol over IRT analysis include improved positive predictive value, reduction of false-positive infants, and more rapid diagnosis with elimination of recall specimens.
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Affiliation(s)
- R G Gregg
- Waisman Center for Mental Retardation and Human Development, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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